Air pump



.Y A- 125.1941' J. R. olsHEl 2,252,661

AIR PUMP `Filed Nov. so, 1958 58 NQZ. 15 10 2yk 14 INVENTOR.

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ATTORNEYS Patented Aug. 12, 1941 AIR PUMP `John R. Oishe, Buialo, N. Y., assignorto Trico Products Corporation, Buffalo, N. Y.

Application November so, 1938, serial. No. 243,230

(cl. 23o- 141) 6 Claims.

`'Ihis invention` relates to huid pumping devices` and more particularly to an improvement in that type of pump which utilizes rotary interengaging impeller members. f L

It has heretofore been proposed to prov-idemechancal take-up, means in connection with fluid pumps of the` type here under consideration. Such take-up devices have usually involved interposing additional `mechanical means between the normally contacting wall of the pump casing and the rotary impelling members.

In my present invention the various elements are so arranged that the rotary elements are held in resilient sealing contact directly against the inner Wall of the pump casing. This construction` simplies and makes more certain the efflcient sealing of the pumping chamber portionof the fluid pump.

In the drawing:

Fig. 1 is an elevational view of my improved pump with the casing cover member removed; and

Fig. 2` a cross-sectional view taken on the line II-II of Fig. 1.

In the drawing the numeral I designates a main casing member which provides a suitable compartment for the operating parts and which '-s closed with a cover member I I, shown in Fig. 2.

Provided within the casing I0 is a. projection or `abutment I2 having two re-entrant arcuately curved faces, the purposes of which will herein- .after be described. The projection I2 is preferably rigidly associated with the casing I0 and in the present instance is illustrated as being integral therewith.

The moving pumping elements are, in the exempliied embodiment, a pair of interengaging gears I3 and I4 which are held in operative engagement by a bracket I5 which has journaled therein the opposite ends of gear supporting stub shafts I6 and I1 respectively. The bracket I5 has spaced parallel bearing portions I8 and I9 and an intermediate connecting portion 2U.

In assembling the pump of the present invention the interconnected gears I3 and I4 are disposed in abutment with the projection I2 in such manner that the outer periphery of each gear rides against one of the previously referred to arcuate faces of the element I2 with the element projecting between the gears almost to the point of intersection of their outside diameters.

Portions 2I and 22' which serve to shroud the gears I3 and I4 in the region of their contact with the projection I2 are provided. Such portions could either be a part of the bracket I5 or integral with thecasing I0. In the drawing, however, the portion 2I is formed integrally with the casing I0 and the portion 22 is formed integrally with the cover member II.

At the point where the element I2 projects farthest between the gears I3 and I4 an aperture 23 is provided which leads to a tube 24 which is connected to the casing I0 by a coupling 25.

One of the impelling members, in the present instance the gear I4, is adapted to be rotated as by mean-s of the iiexible drive shaft 26. The drive shaft 26 enters the casing I0 through an opening 21- which is preferably larger than the drive shaft to permit movement of the impelling members in a direction transverse to their axis of rotation.` If the gears I3 and I4 be rotated counterclockwise andl clockwise respectively as viewed in Fig. ,1, the device will function as a vacuum pump, iiuid from the tube 24 lling the spaces between the gear teeth as they disengage and being carried thereby to the point where they emerge from contact with the projection I2 where the fluid is delivered into the interior of the casing I0 generally. In the case of a gaseous fluid a vent 28 may be provided to avoid building up of pressure in the interior of the casing.

Means are provided for assuring intimate contact between the peripheries of the impelling members and the cooperating surfaces of the projection I2 atvall times. Such means may comprise a coil spring 2'9, one of whose ends bears against the connecting portion 20 of the gear supporting bracket I5. The other end of the coil spring is received within a cup provided in an adjusting screw 30 which is disposed in a threaded opening in the wall of the casing Ill.

The coil spring 29 and the adjusting screw 30 are disposed opposite the projection I2 so that they serve to resiliently hold the gears I3 and I4 evenly against the projection I2. Owing to the particular formation of the arcuate surfaces of the projection I2 and the floating mounting of the bracket I5 which carries the gears I3 and I4 the gears will be self-centering with respect to the projection I2. If desired a boss 3| may be formed upon the back of the connecting portion 20 of the bracket I5 to assist in locating the coil spring 21 thereon.

While a single detailed embodiment of the invention has been illustrated it is to be understood that my invention is not to be considered as limited thereto or in any other way save as defined in the appended claims.

I claim:

1. In a rotary pump, a casing, a pair of inter- 2. In a rotary pump, a casing, a pair of interengaging impelling members adapted to be jointly rotated, means rigidly associated with said v casing for cooperation with the peripheries of` said impelling members to form pump` chambers, means movably mounting said impelling members Within said casing for movement transverse to their axes, and resilient means for urging said impelling members into intimate peripheral contact with said rigid means, said rigidmeans having a fluid passage terminating adjacent said impelling members. Y

3. In a rotary pump, a casing, a pair of interengaging impelling members, a bracket lfor supporting said impelling members for joint rotation, and means associated with said casing for cooperation with the peripheries of Said impelling members to form pump chambers, said bracket being movably mounted in said casing for movement of said impelling members in a direction transverseV to their axes, said casing associated means having a passage terminating in a port adjacent said impelling members for-conducting fluid displaced thereby. f v

4. In a rotary pump, a casing, a pair of interengaging impelling members, a movably mounted bracket for supporting saidimpelling members for joint rotation, said bracket and said impelling members being bodily movable in a direction transverse to the axes of rotation of said impelling members, means associated with said casing for cooperation with the peripheries of said impelling members to form pump chambers, and

reslient means for acting against said bracket to urge said impelling members into intimate peripheral contact with said rst mentioned means, said casing associated means having a uid pas sage arranged for communication with said pump chambers.

5. In a fluid pump, a casing, a pair of interengaging impelling members, means rigidly associated 'with said casing and having a pair of reentrant arcuate faces for bearing against adjacent portions of the peripheries of said impelling members to form pump chambers, a holder for said impelling members for supporting the same in interengaged relationship, said holder being mounted for movement in said casing in a direction ltransverse to the axes of rotation of said impelling members, and resilient means associated with said casing and acting upon said holder for urging said impelling members against said arcuate faces, said rigid means having a fluid passage arranged for communication with said pump chambers;

6. In a fluid pump, a casing, a pair of interengaging impelling members, means rigidly associatedwith said casing and having a pair of reentrant arcuate faces for bearing against adjacent portions of the peripheries of said impelling members, a holder for said impelling members forv supporting the .same in interengaged relationship, said holder being mounted for movementin said casing in a direction transverse to the axes of rotationof. said impelling members, said rigid means including side anges for cooperation with said impelling members and said arcuate faces to form a pump chamber, and means for supporting said holder With said impelling members in abutment with said arcuate faces, said rigid means having a uid passage arranged for communication with said pumpzchambers.

JOHN R. OISHEI. 

